He said: “To end the Operation Grange investigation while there is still work to be done would be disastrous. To say they are in ‘dialogue’ suggests they’re still working on leads.”

Madeleine’s parents Kate and Gerry, from Rothley, Leicestershire, say they have no plans to give up the hunt for their daughter, who would now be 15.

Nearly £12million has been spent on Operation Grange but no firm suspects have been identified. More than 60 persons of interest have been investigated and 650 sex offenders considered possible suspects.

The Home Office gave the Met £154,000 in March to extend their work for six months.